It can be said, without hesitation, that I am a huge fan of the Joker. He's easily my favourite fictional villain and it's a bit of a shame that he's such an unpredictable, savage maniac (even if we love him that way) because it makes him less likely as a leading man candidate for any story in any medium. But, thankfully, there are a few writers who have made an effort to focus on him thoroughly - with varying degrees of success, for one reason or another. Below are three well known comic book (or "graphic novel") appearances of the Joker in, essentially, starring roles. So, how are they all?
THE KILLING JOKE:

Synopsis: Batman visits Arkham Asylum to discuss with the Joker the inevitable outcome of one of them destroying the other, if they continue on as they are, only to find that the Joker has already escaped. Kidnapping Commissioner James Gordon - after shooting and severely injuring his daughter, Barbara - the Joker attempts to drive Gordon insane by giving him "one bad day," while Batman struggles to find and capture his enemy before it's too late. Alongside the present day story, a series of flashbacks give insight into the history of the man and the one bad day that drove him into becoming the Joker he is famous for.
It might sound entirely strange if I criticize this work for being unrealistic and having little real human meaning. An obvious response is to say, "The guy's origin story is falling into a vat of fuckin' chemicals and crawling out with skin and hair of a different colour!" And that's very true but, for me, a truly successful Batman comic requres a balance between farce and realism. The method of the Joker's creation (i.e. chemicals) is a pure farce - in a good way. The token victimisation and plea for sympathy of former Joker ("Jack"), however, feels like farce in an element that should have contained more human reality.
I like that Alan Moore tried to take the Joker in a more psychological direction than was popular at the time. The flashbacks here are a nice nod to Bob Kane's original origin story of the simple but enigmatic Red Hood, whose tumble into bizarre chemicals made him an even deadlier criminal. Moore has expanded on the premise and created a full chain of events. What he was doing there, his part in the group and the scene of his first meeting with Batman, pre transformation. An element of the Joker's power in our culture, though, is that he is mysterious. There is no bottom line on this man. He has no beginning, he has no end and he certainly has no limits. The weak explanatory backstory here simply detracts something from the Joker mythos, rather than truly adding to it. It also comes off as something artificial and shallow. Barring the obvious disfigurement, most people who (hypothetically) undergo Moore's tragic explanation might have become chronically depressed, turned to alcoholism - or suicide - and called it a day. Not gone inordinately psychotic and become randomly committed to a life of crime.
It's also counter-intuitive to the emotional dynamics of the book. While Jack's desperation and victimisation is piled on in one half of the story, our fully formed Joker commits some of his most crippling and unashamed crimes in the present day. Any work towards sympathy (or even empathy) towards this character is dashed away instantly. We can't empathise with the Joker - that's one of his main traits! Does suffering earlier in life give pardon to atrocities committed later on? Does a simple loser, who's taken advantage of, really become such an irredeemable force violence and trauma because of one bad day? Who knows. Maybe Alan Moore doesn't even know.
I'll admit that the concept of "One bad day makes people insane, in different ways" is a working Batman theme. Bruce Wayne, for example, has been driven to a kind of madness by the death of his parents, which fuels a quest that will never truly be able to end. The motivation and desire behind the Joker's psychological scheme in this book, though, has the air of an attempt that is more likely to occur early in both men's careers, rather than much later, when they understand the desires and dynamics between them so well after a long rivalry.
Perhaps the worst part of the writing is the portrayal of the Joker's "insanity." Sure, he explains how he went insane. But his explanation of it all is perfectly sane and well reasoned. In fact, everything the Joker does in this book is either sane or simply random - carried out for the sake of acting randomly: as if the Joker is trying to prove his insanity, instead of just living it. This characterisation feels somewhat like Cpl. Klinger from the TV show M*A*S*H; who had a habit of wearing women's clothing, in an attempt to prove some insanity, so that he might be sent home. I'm not trying to completely rag on this story. The art and storytelling structure is really fantastic. This book has interesting details, was innovative at the time of its release and does have its highs. But, ultimately, I don't feel there's anything powerful or compelling enough here for it to deserve the "masterpiece" status that so many readers and Joker fans have given it.
LOVERS AND MADMEN:

Synopsis: Set at the beginning of his famous career, Bruce Wayne feels confident that his war on criminality is progressing smoothly. After years of having privately studied law-breakers, their motivations, sub-cultures and rules, the Batman has begun to make a clean sweep of Gotham's streets. At the same time, Jack, a prodigious career criminal, has become weary of meandering through his work without any challenge or spark to engage him - until he witnesses the costumed Batman. When the crossing of their two paths becomes personal to Bruce, his emotions and professionalism are put to the test, and Batman's greatest enemy is born from the conflict.
This alternate Joker origin is not The Killing Joke, which is fine, for my tastes but, from what I've seen, it's when people start comparing this story to that one that they start quoting problems with it and that's a real shame. This is a younger Batman; one who hasn't become his true self yet - who hasn't adapted to life with dual identities and come to the values that will make him the Batman that he needs to be. Bruce makes mistakes. Upon meeting Jack, a being outside of his comprehension and expectations, his confidence in his crime-fighting abilities almost shatters. As Batman himself says of his experiences: "I expected to run into monstrous men, not monsters." This raging, frustrated, terrified - very human - Batman is still fresh on the job. Opposite him is a calm, fearless sociopath, whose only emotional range seems to be either boredom or amusement. In the words of Dr. Jonathan Crane: "He's not a criminal. This isn't crime. This is evil."
The art in this book fits the characters and story very well. Linework is somewhat layered and sketched; not clean. It's not a style for everyone but there are moments where you just get caught up in the precision of the mess. There's a ragged incompleteness and, yet, an alluring beauty to the Batman and Joker figures - similar to the characters themselves and our emotional reaction to them. For most of the plot, our villain is his plain, human self and it's only at the climax that he becomes the clown we all know and love. The difference is, mostly, cosmetic though - his schtick already incorporates theatrical robberies and murder.
The character's background is still (like The Killing Joke) undeveloped and weak, given that the writer is trying to invent an entire origin story in a little less than 150 pages. There are scenes or elements that are a bit pulpy in here but the energy and connection between Batman and his archenemy is very present. The emotional/psychological shift from mere gifted criminal to the Joker feels much more humanly plausible in this story as well. His growth into the man he becomes isn't as impossibly drastic; it feels closer to a logical progression. This is a book that balances superhero farce and frail humanities in a better way than The Killing Joke does, in my opinion.
Batman and the Joker don't have quite the intimate connection here that might be found in other stories: that one-half-a-bickering-married-couple/other-half-a-knight-battling-a-dragon dynamic. Lovers and Madmen is two emotionally muddy men, still trying to find the right role to play. But this is the spark that begins it all.
JOKER:

Synopsis: Told from the perspective of Jonny Frost, a low level worker in the Gotham criminal network, our main character agrees to pick up the Joker, who is - for reasons unexplained - being released from Arkham Asylum that day. When the Joker sets out to reclaim the respect and control of the city and his gangster underlings, Jonny sees an opportunity to climb the criminal ladder by helping out and gaining the Joker's favour. But, as more villains enter the fray and the Joker's actions become more rabid, Jonny may discover that the lifestyle he yearned for is more than he can handle.
The first thing to be said for this is that the artwork is often mouth-watering. And, given this frequent quality, it's bizarre to see Lee Bermejo switch, seemingly at random, throughout the story, between masterfully painted comic frames into very hum-drum, by comparison, regular outlines and ink work. Regardless of this incomprehensible decision, there are panels in this book that would look godly if mounted on a wall. The Joker has rarely looked as convincingly skin-crawlingly creepy than in these pages. But each one of these books has some arguable flaw or distinct peculiarity. The Killing Joke is far too short. I feel rushed through it, never getting a chance to properly dig into (or be dug into by) the Joker. Lovers and Madmen completely undresses the Joker creation myth and puts it in clothes that are almost the opposite of anything that people had expected to read before. However, both of those books maintain a critical element that this title sorely lacks.
I’m fine with this seedy, realistic tone of Gotham City's underbelly and its inhabitants. Sure, I love gadgets, crazy bullshit and fantasy stories as well but I don’t feel that realism inherently deprives Batman's universe of anything. It’s the writing of the Joker himself that fails here; what sucks is that he has no unique scale. Apart from being more violent than other characters here, he’s no more larger-than-life than anyone else. Sure, he’s psychotic ... But Charles Manson and countless other random weirdos have been psychotic too.
You could pretty much restyle the Joker’s face to a regular person’s and edit his name into Alberto Moscone, or some other cliché street thug name, and this would would, essentially, be exactly the same story. There’s nothing particularly special about him being the Joker here and that’s a huge problem.
The Joker needs to be more than just a criminal, like all the people around him are. The significance of Batman’s major “Rogues Gallery” (Two-Face, Poison Ivy, Scarecrow, etc) is that they’re not regular law-breakers. They’re special - with the Joker, arguably, being the most special of all. This guy needs to be epic and grand; not just in his mannerisms and behaviour but in his psychology and strategies. It fits that he can be hideously violent, beyond the scope of what else we might see from others (and this story certainly is violent) but that can’t be the only thing that differentiates him from the rest of the underworld.
One of the things that made the Joker in Christopher Nolan's film, The Dark Knight, so powerful is that, despite the face make-up, guns and conceptual simplicity, Heath Ledger tapped into the Joker's subtleties so definitely. His manic aggression and hilarious, fatal sense of humour, and - most importantly - his perfect sense of presence and authority. Azzarello's story here isn't in the same league. I’m not saying I hate this work because I don’t. It certainly has its strengths. Realistic, urban interpretations of Batman villains are valid in theory, too, since you can be true to the Joker without needing fantasy. This book just doesn’t deliver him. It only gives us a blend of Scarface and Goodfellas, which is pretty regular.